French divers recently found a large cave along the coast of the Medit

The water in cave can evaporate, get out with waves etc. How can we be sure that water level will rise.

Hi desertEagle.

The correct answer doesn't say that the water level will rise. It says that the water level is now higher than it once was.

Take another look.

The point is that, if the cave is now full of water, but it has structures in it that form through the dripping of water, then the water level must once have been lower.

Why is D not correct? the water must have fallen from an entrance point on the floor. Unless there is an entrance point/hole on the top of the cave, water would not fall right?

Here's (D).

(D) There was once an entrance to the cave besides the underwater tunnel.

The truth is that what the passage says doesn't really give us a reason to believe (D).

After all, the tunnel that is now underwater could have been the way water got to the top of the cave to form the stalagmites. For all we know the tunnel would have allowed rainwater to get to the top of the cave.

Also, it could be that water would drip from the top of the cave after condensing there.

So, the stalagmites could have formed without (D) being true.

French divers recently found a large cave along the coast of the Mediterranean Sea. The cave is accessible only through an underwater tunnel. The interior of the cave is completely filled with seawater and contains numerous large stalagmites, which are stony pillars that form when drops of water fall repeatedly on a single spot on a cave floor, leaving behind mineral deposits that accumulate over time.

The information above most strongly supports which one of the following?

(A) The Mediterranean Sea was at a higher level in the past than it is now. - WRONG. The formation of stalagmite would not have been possible.

(B) The water level within the cave is higher now than it once was. - CORRECT. If not then accumulation of mineral deposits is questionable.

(C) The French divers were the first people who knew that the tunnel leading to the cave existed. - WRONG. Totally not inferable.

(D) There was once an entrance to the cave besides the underwater tunnel. - WRONG. Not necessarily as there could well be many and none.

(E) Seawater in the Mediterranean has a lower mineral content now than it had when the stalagmites were being formed. - WRONG. It is possible either way.

Answer B.